The present application relates generally to semiconductor devices, and more specifically to the integration of semiconductor structures such as switch field effect transistors into radio frequency (RF) devices.
Wireless communications use an antenna to transmit and receive electromagnetic (EM) signals. The antenna is typically driven by an integrated circuit (IC) or other discrete device. This IC or driver chip may be configured within a package on a printed circuit (PC) board, for example, along with other circuitry. The EM signal from the driver chip reaches the antenna via internal wiring or other metallization.
There is an increasing demand for compact radio communications systems having integrated transmitter, receiver, transceiver and antenna systems, which enable high data transmission rates, high volume, low power consumption, low weight, and low cost. As operating frequencies increase, the manufacture and assembly of such systems becomes increasingly difficult due to the requirements of high-precision machining and accurate alignment.
Radio frequency devices, including devices operating at 1 GHz and greater, are beneficially integrated directly onto a semiconductor substrate such as a semiconductor-on-insulator (SOI) substrate. However, voltage imbalances caused by substrate loss as well as floating-body and parasitic capacitance effects between input and output electrodes can contribute adversely to the non-linearity of a semiconductor-on-insulator FET switch.
It would be advantageous to provide a method and structure for providing RF isolation to minimize or eliminate parasitic capacitance in switch FETs and other device types to meet linearity specifications.